The present invention relates generally to high speed connectors, and more particularly to a connector for terminating a cable having multiple distinct signal channels, each channel including at least a pair of differential signal wires and terminals.
Many shielded connectors are known in the art, in which an insulative connector housing is provided to support a plurality of conductive terminals. The housing may have a metal ground shield to provide additional grounding for the connector and for signal isolation. Notwithstanding the presence of the exterior shield, a separate ground pin is often provided in the connector housing. The external metal shield may use either crimping or a butt contact to hold it together. Such a shield structure is not mechanically robust. This type of shield member also uses interlocking members stamped at the ends of the shield member. The use of these members at that location reduces the ability to use the ends of the shield for shielding purposes.
In multiple-channel connectors, the signal terminals of each channel are typically arranged together in side-by-side order along a mating surface of the connector. These signal terminals are not isolated from each other, which may lead to crosstalk occurring between the signal channel wires, thereby hampering the electrical performance of the connector.
Historically, in multiple-channel connectors, the outermost signal terminals have had a particular electrical relationship to the outer metal shield both to the bottom wall and the vertical sidewalls of the shield. These outermost conductive terminals have a greater electrical affinity to the shield than do the innermost conductive terminals because the innermost terminals are spaced relatively far away from the vertical sidewalls of the shield and have no vertical shield wall close to them. Consequently, the innermost terminals display an electrical affinity for each other rather than to the shield, thereby resulting in crosstalk between them which may lead to potentially degrading interference of signal transmission through the terminals, especially in high speed electrical transmission lines. The electrical relationship between the signal terminals and the outer shield of the connector is therefore potentially unbalanced in these known shielded connectors.
The present invention is directed to a shielded, multi-channel connector having a balanced electrical field relationship between its signal terminals and the shield of the connector.